package 力扣日常刷题.木22二月.第15天221;

/**
 * @author 帅小伙
 * @date 2022/2/21
 * @description
 */
public class Demo120把字符串转换成整数 {


    public int strToInt(String str) {
        char[] c = str.trim().toCharArray();
        if(c.length == 0) return 0;
        int res = 0,bndry = Integer.MAX_VALUE/10;
        int i = 1,sign = 1;
        if(c[0] == '-') sign = -1;
        else if(c[0]!= '+') i = 0;
        for (int j = i; j < c.length; j++) {
            if(c[j] < '0' || c[j] > '9') break;
            if(res > bndry || res == bndry && c[j] > '7') return sign == 1 ? Integer.MAX_VALUE: Integer.MIN_VALUE;
            res = res * 10 + (c[j] - '0');
        }
        return sign * res;
    }

}
